const Koa = require('koa');
const app = new Koa();

app.use((ctx, next) => {
    console.log(1);
    next();
    console.log(4);
    
});
app.use((ctx, next) => {
    console.log(2);
    next();
    console.log(5);
});
app.use((ctx, next) => {
    console.log(3);
    next();
    console.log(6);
});

console.log(app);
app.listen(3000, () => {
    console.log(' koa server start!');
});